1. Field of the Application
The present application relates to a method of resin injection molding. More particularly, the present application relates to a method of molding a composite part with a metal sheet forming a surface of the composite component which is injection molded. The present application also relates to a composite molded casing of a turbomachine compressor according to the present application.
2. Description of Related Art
The weight of an axial turbomachine, in particular in an aircraft, must be reduced. To achieve this goal, it is necessary to reduce the weight of its casing. The reduction is possible by using composite materials for producing, for example, an outer casing of the compressor. However, such an outer casing may have a metal insert, for example a strip which serves as a gripping surface for an annular layer of abradable material. This is beneficial because the adhesion of an abradable layer is better on a metal than on a composite material.
It is known from document EP2418387A1 a compressor casing of an axial turbomachine. The casing comprises a composite wall with a metal strip applied on the inner surface of the casing. The composite wall is formed from a preform disposed in a mold where it receives an injected resin in a RTM process. The strip is attached to the composite wall after molding by using glue. This embodiment of a compressor casing is used to link a composite casing and a metal strip. However, the positioning of the strip in the housing is complicated due to the curved shape of the casing.
To simplify the implementation of the strip, it is known to those skilled in the art to position the strip against a mold surface and then to dispose above the preform of the composite part. The strip is held by the preform which is itself locked in position by the mold when it is closed. However, the pressure of the injected resin can move and deform the preform. Therefore, the strip can move substantially and can no longer occupy its predetermined place.
Although great strides have been made in the area of injection molding, many shortcomings remain.